Synacthen test results- any advice?

Hi everyone,

I'm not posting specifically about PMRGCA so my apologies but I have been trying to find a forum where people have experience of cortisol testing and it seems that a few have on here.

The results are as follows-

Morning cortisol- 78 so referred for synacthen test.

Morning cortisol 95 on day of synacthen test.

Cortisol response to synacthen was 475 with a cut off from that particular lab of 500 (I know this varies between labs).

The endocrinologist has said this result is borderline, that the adrenals show enough reserve to show a large increase on stimulation. Since it was technically a fail they are going to repeat in a few months time.

I'm not sure what to think. I understand that the response was very close to 500 but on the other hand, both of the morning cortisol levels were very low and the synacthen test result was still technically a fail. The endocrinologist has not suggested any treatment, use of steroids etc. and this concerns me from what I've been reading about the risk of adrenal crisis.

Main symptoms are tiredness, low immunity and lots of infections, not on steroids or any other medication. Thanks for any experience/ advice/ perspectives.

[PMRpro Ambassador]

What the synacthen test shows is that the adrenal glands are CAPABLE of producing cortisol when stimulated by ACTH which is what would happen normally. What it doesn't show is whether that is happening reliably and consistently in day to day functioning and the impression I get is that that isn't happening too well. However - the basal cortisol had risen between the 2 samples which is promising.

The adrenals producing cortisol is not a stand-alone thing, it is dependent on a whole complicated relationship between the hypothalamus, pituitary and adrenal glands, know as the HPA axis, and it includes those three organs AND a load of hormones, Until they are all in balance you will have abnormal results.

Obviously the endocrinologist is satisfied you are safe to leave for now and see if the basal cortisol improves. I am surprised he didn't educate you on an adrenal crisis and what to do and issue a rescue pack of hydrocortisone but he's the expert.

I think you do need to know the warning signs and make sure whoever you live with knows and possibly work colleagues. If you think you are threatening a crisis, feel really unwell, are confused, weak and wobbly, call 999 and tell them possible adrenal crisis, I would make a notice and put it on the fridge with your history and carry it in your handbag, It sounds dramatic - but infinitely better to be prepared and never need it than the other way round! We are all in the position of having pred to hand but you have to be well enough to swallow the pills! I would also have a discussion with your GP, explaining why you are concerned. I don't think he can authorise the rescue pack but he may get more response from the endocrinologist with regard to your concerns.

Good luck - and do tell us how you get on.

[Avadip12 in reply to PMRpro]

can I ask you please , that if my synatchen test was normal last year 400 before ACTH injection and 560 30 mins later . As my symptoms regarding my morning shut down and unable to drive or connect to the world until midday plus. My rheumatologist has now asked for morning cortisol. I am not sure if it will be any different ?? Can u offer any light . Problem being that all this is being done by letters back and forth from GP

[PMRpro Ambassador in reply to Avadip12]

All depends doesn't it - maybe something has happened that has messed up your adrenal function. At least he's only doing a basal cortisol - it tells you almost as much as the synacthen if you are normal or insufficient without going to the bother of getting a day clinic appointment for a synacthen test, If it is decent it will suggest the symptoms are possibly due to PMR rather than adrenal problems.

[Avadip12 in reply to PMRpro]

thanks for that super quick reply .

[Hidden in reply to PMRpro]

Thank you so much for your very detailed reply. I'm reassured by your comment about the adrenals being able to respond, I agree this is a good sign. I was also surprised that the Endocrinologist never mentioned anything about illness or steroids etc and basically said there's no real issue. The repeat test it seems is more of a formality due to this one being below the cut-off. What I cannot understand and endless googling is not helping me, is why the baseline cortisol level is so so low. Everything I have read says that a morning level below 100 is basically a diagnosis of adrenal insufficiency and further testing isn't even needed. I'm finding that really confusing and as you say, if the adrenals can respond to stimulation, why are they not doing so.

[PMRpro Ambassador in reply to Hidden]

Because there are an awful lot of steps that have to be right - maybe it is another one that is wobbly? But I'd want a bit of investigation before assuming that cortisol was fine.